Classifications

• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03K—PULSE TECHNIQUE
  • H03K19/00—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits
  • H03K19/003—Modifications for increasing the reliability for protection
  • H03K19/00315—Modifications for increasing the reliability for protection in field-effect transistor circuits
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
  • H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
  • H01L21/76—Making of isolation regions between components
  • H01L21/761—PN junctions
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
  • H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers
  • H01L27/04—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body
  • H01L27/08—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body including only semiconductor components of a single kind
  • H01L27/085—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body including only semiconductor components of a single kind including field-effect components only
  • H01L27/088—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body including only semiconductor components of a single kind including field-effect components only the components being field-effect transistors with insulated gate
  • H01L27/092—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body including only semiconductor components of a single kind including field-effect components only the components being field-effect transistors with insulated gate complementary MIS field-effect transistors

Definitions

• the invention relates to a circuit for driving the gate of a MOSFET or IGBT, and more particularly to an integrated gate driver output stage with a bias circuit which provides a high and wide operating voltage range.
• Fig. 1 shows a conventional CMOS push-pull output stage comprising MOSFETs MlOO and M200 for driving the gate of a discrete MOSFET or IGBT.
• Fig. 2 shows a conventional NMOS totem pole output stage comprising MOSFETs M100' and M200 for driving the gate of a discrete MOSFET or IGBT.
• the maximum operating voltages of the circuits in Fig. 1 and Fig. 2 are determined by the respective voltage differences between the drain and source nodes of MlOO and M200, or M100' and M200. If the voltage difference across one of these MOSFETs is higher than the maximum drain-source breakdown voltage of the IC device, breakdown occurs, causing the output driver to lose its functionality.
• the invention provides a gate driver that can operate at a higher voltage than the normal maximum voltage rating of its IC devices, and over a wider voltage range. [0006] It also provides a gate driver having a variable output voltage that can be set by an integrated bias circuit. [0007] Also provided is a bias circuit for a gate driver.
• One aspect of the invention relates to an output stage for a drive circuit
• first and second semiconductor devices each having a respective pair of main terminals, one main terminal of each of said devices being connected in series to form a half -bridge, an output drive signal being supplied at said connection point, each device further having a respective control terminal, said control terminals being connected together to receive a control signal; and a third semiconductor device having one main terminal which receives a supply voltage, another main terminal connected in series with said first device, and a control terminal for receiving a bias voltage, said third device being controllable by said bias voltage for variably reducing said supply voltage to prevent said supply voltage from being fully applied to said first and second devices.
• a bias circuit may be integrated in said semiconductor chip, the bias circuit comprising: a fourth semiconductor device having a first main terminal which receives said supply voltage and a second main terminal which supplies said bias voltage to said control terminal of said third device; a voltage divider connected at one end to said third device control terminal and at another end to a common point; an error amplifier having a positive input receiving an output of said voltage divider and a negative input receiving a reference voltage referenced to said common point; said error amplifier having an output driving a control terminal of a fifth semiconductor device, one main terminal of said fifth device being connected to a control terminal of said fourth device, the other main terminal of said fifth device being connected to said common point; and a resistance connected between said supply voltage input and the control terminal of said fifth device.
• the bias circuit generates a bias voltage determined by the equation:
• V R2 V BIAS P - — /? -V REF
• a further aspect of the invention relates to a method for increasing the operating voltage range of an output stage of a drive circuit, said output stage comprising: first and second semiconductor devices each having a respective pair of main terminals, one main terminal of each of said devices being connected in series to form a half -bridge, an output drive signal being supplied at said connection point, each device further having a respective control terminal, said control terminals being connected together to receive a control signal.
• the method comprises the steps of: providing a third semiconductor device having one main terminal which receives a supply voltage for said output stage, another main terminal connected in series with said first device, and a control terminal for receiving a bias voltage; and controlling said third device by adjusting said bias voltage, for variably reducing said supply voltage to prevent said supply voltage from fully being applied to said first and second devices.
• the step of adjusting said bias voltage may thereby adjust a voltage drop across said third device.
• the step of adjusting said bias voltage may also thereby adjust a voltage of said output drive signal.
• the present invention provides a simple, low cost, gate driver and bias circuit having a higher component breakdown voltage than in conventional CMOS, NMOS and PMOS arrangements and a wider operating voltage range.
• a CMOS device with an epitaxial layer on a p-type substrate may be used to implement the circuit.
• Fig. 1 shows a conventional CMOS push-pull output stage for driving the gate of a discrete MOSFET or IGBT;
• Fig. 2 shows a conventional NMOS totem pole output stage for driving the gate of a discrete MOSFET or IGBT;
• Fig. 3 shows a first embodiment of the invention comprising a CMOS device with an epitaxial layer as a bulk layer formed on a p-type substrate;
• Fig. 4 is a schematic diagram of a CMOS push-pull output stage corresponding to the embodiment of Fig. 3; [0016] Fig.
• Fig. 5 is a schematic diagram of an NMOS totem pole output stage according to a second embodiment of the invention
• Fig. 6 is a schematic diagram of a bias circuit including an op-amp
• Fig. 7 is a schematic diagram of a bias circuit including a comparator
• Fig. 8 is a schematic diagram of a gate driver circuit including the push-pull driver of Fig. 4 and the bias circuit of Fig. 6.
• Fig. 3 shows a first embodiment of the invention including a CMOS device 20 with an epitaxial layer 21 formed on a p-type substrate 22.
• Integrated MOSFETs Ml, M2 and M3 in Fig. 3 correspond to the same elements shown schematically in Fig. 4.
• the top transistor Ml in Figs. 4 and 5 is connected in series with the output transistors M2 (M2 and M3 and provides a variable voltage drop according to the applied bias voltage. It thereby keeps the drain voltage of the middle transistor M2 (M2 7 ) lower than the breakdown voltage even when the supply voltage N cc is higher than the breakdown voltage.
• the output voltage N ou ⁇ can also be adjusted.
• Ml is in the high side well to isolate it from M2 and M3 which are in the low side well.
• Ml is placed in the high side well since the voltage difference N cc is applied between Ml and the epitaxial layer 21. Isolating Ml from the other transistors ensures that N cc will not be applied to the transistors M2 and M3.
• the circuits in Fig. 4 and 5 to operate properly need a controlled bias voltage V BiAS on e g ate °f Ml.
• the gate bias voltage can be generated by many topologies.
• Figs. 6 and 7 show two possible examples 35 and 35'.
• This topology has the advantage when the voltage difference between N cc (V m ) and N BIA s is very small. Other topologies may be used when V cc is lower than N BIAS or slightly higher than N BIAS .
• an error amplifier 29 (op-amp 30 in Fig. 6, comparator 31 in Fig. 7), receives a reference voltage at its negative input, and at its positive input receives the voltage VD at the midpoint of a voltage divider Rl, R2.
• the error amplifier 29 turns on a switching device M20 of one conductivity type.
• a first main terminal of the switching device M20 is grounded, and the second is connected to a control terminal of another switching device M10 of the conductivity type opposite to that of M20.
• the two main terminals of M10 are connected respectively to the supply voltage N m (N cc ) and the N BIAS output terminal.
• a resistor R3 is connected between N and the control terminal of M10. [0025] M10 and R3 in Fig. 6 and 7 are located in the high side well, in the same fashion as Ml in Figs. 4 and 5.
• the output voltage N BIAS is determined by equation (1) below.
• Fig. 8 shows an integrated gate driver circuit 50 including the push-pull driver of Fig. 4 and the bias circuit of Fig. 6. Also seen is control circuitry 40 for supplying control signals to the output circuit 20 as needed for a particular application. If M10, Ml, and R3 are in the high side well in Fig. 5, and N BIAS is set at N cc /2 by Rl and R2, then the voltage N ou ⁇ has a range from 0 to N cc /2, so that a voltage V J ⁇ which is twice as high as the normal maximum operating voltage can be applied. The threshold voltage of Ml is neglected because it is small compared to Vcc- C ou ⁇ may maintain the level of N BIAS and may also ground any high-frequency transients that occur.
• C ou ⁇ may be implemented internally or outside the IC. Whether the circuit will operate reliably without C ou ⁇ and the value of C ou ⁇ can be determined by routine experimentation. [0027] Advantages of using the circuit topologies described above are that (1) the chip size is reduced because the size of a component such as a MOSFET is proportional to its maximum voltage rating, (2) cost savings are achieved due to the smaller chip size, (3) the operating voltage range is wider than in conventional circuits, and (4) fast response time is easily achieved due to the small component size and the other features disclosed. [0028] Although NMOS and CMOS components are used as examples in this disclosure, PMOS components could also be used with suitable circuit modifications. [0029] Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. Therefore, the present invention is not limited by the specific disclosure herein.

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• Semiconductor Integrated Circuits (AREA)
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• 2005
  • 2005-05-16 US US11/130,370 patent/US7292088B2/en active Active
  • 2005-05-18 WO PCT/US2005/017273 patent/WO2005117144A2/en active Application Filing
  • 2005-05-18 KR KR1020067026798A patent/KR100846880B1/ko active IP Right Grant
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